final exam 83

Oldd Final Exam

1. Which of the following is the largest volume? a) 1.0 dm³ b) 100 cm³ c) 1001 ml d) 0.11 m³

2. Cathode rays are: a) protons b) neutrons c) positively charged ions d) electrons e) negatively charged ions

3. Which of the following of Dalton's postulates of atomic theory is not true? a) Each element is composed of atoms b) All atoms of an element are identical c) Atoms of different elements have different properties d) Atoms are not changed (the nucleus that is) in chemical reactions

4. Which of the following is smallest? a) microampere b) nanoampere c) milliampere d) picoampere e) megaampere

5. The attraction of electrons of an atom to the nucleus is explained by: a) the strong nuclear force b) the presence of neutrons c) electrostatic attraction d) the Law of Charge Conservation e) none of the above

Answers: d, d, b d, c

7. Which of the following is chlorous acid? a) HClO4 b) HClO3 c) HClO2 d) HClO

8. What is the total number of nuclear protons in a mole of Fe(OH)3? a) 3.19 x 10²⁵ b) 1.81 x 10²⁴ c) 6.44 x 10²⁵ d) 6.02 x 10²³ e) 2.11 x 10²⁵

9. Manganese (IV) oxide and hydrogen chloride react as shown below:

MnO2 + 4 HCl ---> MnCl2 + Cl2 + 2H2O

If 18.6 g of MnO2 and 40.0 g of HCl yield 26.8 g of MnCl2, 15.0 g of Cl2 and 7.7 g of H2O; what is the limiting reagent? a) MnO2 b) HCl c) MnCl2 d) Cl2 e) H2O

10. A reaction in which energy is given off is known as a) loganthmic b) endothermic c) cotaleptic d) exothermic e) lycanthropican

Answers c, a, a, d

11. The heat of combustion of CH4 is 802 kJ/mole. How much energy (kJ) is liberated by burning 4.0 g of CH4? a) 201 b) 1604 c) 401 d) 80.2 e) 3208

12. Standard enthalpies of formation are: NH3(g)-46.2 kJ; NO(g) 90.4 kJ; H2O(g) -242 kJ. What is H for 4NH3(g) + 502(g) ---> 4NO(g) + 6H2O(g) a) -106 b) -906 c) +378 d) -414 e) +624

13. The heat capacity of water is 4.18 J/C-g. How much energy (J) is needed to heat 25 g of water from 40C to 75C? a) 105 b) 875 c) 3658 d) 146 e) 35

14. The wavelength of a radiation which has a frequency of 2.40 x 10^-6/sec is _____ m. a) 6.42 x 10^-4 b) 3.15 x 10^-8 c) 8.20 x 10² d) 1.25 x 10¹⁴ e) 4.40 x 10¹⁰

15. If the energy of a photon is 6.24 x 10^-20J, its frequency is _____/sec. a) 4.24 x 10^-6 b) 9.43 x 10¹³ c) 6.24 x 10¹³ d) 3.00 x 10⁸ e) 9.11 x 10^-28

Answers a, b, c, d, b

16. Which of the following is an incorrect designation for an atomic orbital? a) 14s b) 3p c) 2f d) 5d e) 2p

17. How many different atomic orbitals are there that can have the designation n = 4? a) 3 b) 10 c) 16 d) 7 e) 2

18. Which is the maximum number of electrons in a 4f orbital? a) 7 b) 14 c) 10 d) 6 e) 2

19. Which of the following is not a permitted set of quantum numbers? a) l= 3, ml= -3 b) l= 2, ml=O c) l= 1, ml= -2 d) l= 2, ml=2 e) l= 3, ml= -1

20. Based on their positions in the periodic table, select the atom with the largest radius. a) Al b) P c) Si d) Ga e) Ge

ANswers c c, b, c, d

21. How many unpaired electrons are there in the ground state of the Fe atom? a) 6 b) 2 c) 4 d) 3 e) 0

22. What is the maximum possible number of electrons in the atomic orbitals designated by the quantum numbers n = 4 and l = 1. a) 6 b) 10 c) 2 d) 14 e) 8

23. The alkaline earth elements are characterized by what outer electronic configuration? a) np³ b) ns¹ c) ns² d) np⁵ e) nd³

24. Which of the following would have the largest ionization energy? a) Be b) Al c) B d) Si e) C

25. Which element possesses the electronic configuration of [Kr]5s²4d¹⁰5p¹?

a) Ga b) In c) Tl d) Y Cs

ANswers c, a, b, e, b

26. For which of the following can resonance structures be drawn? a) C2H2 b) H2S c) ClO^- d) NO2^- e) BF4^-

28. Given the following bond energies, estimate H for the following reaction. Bond energies and the answers are in KJ/mole. H-O (463) C-O (358) H-H (436) C=O (800) C-H (413) C O (1072) C O + H-O-H -----> H-H + O=C=O a) -528 b) -272 c) +48 d) -38 e) +272

29. Which of the following is least electronegative? a) Mg b) B c) C d) Al e) Be

30. When the correct Lewis dot structure is drawn for CN-, how many electrons are there between C and N? a) 2 b) 3 c) 4 d) 5 e) 6

Anwers d, d, a, e,

31. Which of the following is most likely to be bonded covalently? a) K2S b) SiH4 c) BaCl2 d) FeO e) ZnF2

32. Which of the following molecules is polar? a) CO2 b) F2 c) BF3 d) NH3 e) CF4

33. The angle characteristic of the maximum separation of 3 sets of electrons is a) 90^o b) 109^o c) 120^od) 180^o e) 360^o

34. Indicate the hybrid orbitals used by carbon in the compound H2CO. a) sp b) sp² c) sp³ d) sp²d e) sp²d²

35. How many pi bonds are present in the molecule HCN? a) 0 b) 1 c) 2 d) 3 e) 4

Answers b, d, c, b, c

36. If the bond of a molecule lies on the x axis, overlap of two px orbitals produces a _____ bond. a) ionic b) delta c) pi d) sigma e) banana

37. Write down the molecular orbital configuration for molecular ion NO^- . The species has a bond order of _____ with _____ unpaired electrons. a) 2,1 b) 1,2 c) 2,2 d) 2,4 e) 3,2

38. A gas that occupies a volume of 7.5 L at 6.5 atm will occupy a volume of _____ L at 760 mm Hg pressure if the temperature is kept constant. a) 1.2 b) 22.4 c) 0.75 d) 660 e) 49

39. What is the pressure of 48 g of O2 confined to a volume of 16 L at 25oC? a) 2.3 atm b) 0.44 atm c) 28 atm d) 112 atm e) 23 atm

40. The density of carbon dioxide at 745 mm and 65oC is is _____ g/L. a) 5.78 b) 3.06 c) 2.56 d) 1.56 e) 1.06

Answers d, c, e, a, d

41. Gas A has a molecular weight of 64 AMU. The rate of diffusion of gas B is twice that of gas A. The moleclar weight of gas B is _____ AMU a) 4.0 b) 16 c) 32 d) 128 e) 256

42. Which statement is true? a) Sublimation is an exothermic process. b) The density of a liquid is equal to the density of its vapor at the boiling point. c) Liquids of high vapor pressure have high boiling points. d) A gas can be condensed into liquid only above its critical temperature. e) The solid, liquid, and gas phases of a substance can be in equilibrium at its triple point.

43. The intermolecular attraction present in ethyl chloride (CH3CH2Cl) consists of a) London forces only b) dipole-dipole forces only c) London force and dipole-dipole force d) hydrogen bonding only e) London force, dipole-dipole force, and hydrogen bonding

44. Which substance would have the highest boiling point? a) CO2 b) KBr c) SF6 d) H2O d) CCl4

45. A substance in the liquid state with a low boiling point is most likely to be a) an ionic compound b) a molecular substance c) a network covalent substance d) a metal e) a polymer

Answers b, e, c, b, b